Power-propelling unit for bicycles



POWER-PROPELLING UNIT FOR BICYCLES Filed Dec. 29, 1945 3 Sheets-Sheet lMay 29, 1951 M. VIRATELLE POWER-PROPELLING UNIT FOR BICYCLES 3Sheets-Sheet 2 Filed Dec. 29, 1945 #1: Afr

May 29, 1951 M. VIRATELLE POWER-PROPELLING UNIT FOR BICYCLES 3Shets-Sheet 3 Filed Dec 29, 1945 Patented May 29, 1951 UNITED STATESPATENT OFFICE Application December 29, 1945, Serial No. 638,079 InFrance March 10, 1941 Section 1, Public Law 690, August 8, 1946 Patentexpires March 10, 1961 1 Claim. '1

This invention has for its object to devise a self-contained compact andlight power propelling unit, generally applicable to light vehicles ofany types, but more particularly to bicycles, tandem cycles, tricycles,quadricycles, etc.

The invention also has for its object to devise an arrangement such thatthe propelling unit may be housed in such a narrow space that a bicyclewheel equipped with said driving unit forms an integral unit which canbe mounted in the fork of a conventional bicycle, preferably the rearfork. Another object is to reduce the weight and secure a distributionof the various masses in such manner that the device may be used onconventional bicycles, no matter how light the frame thereof.

Another object of the invention is to provide a construction which doesnot interfere with the propulsion of the vehicle by the pedals, byshifting the speed gears to dead center, whereby the wheel will onlydrive the hub, the inertia of the rotating parts not being substantiallyin excess over that of a conventional bicycle wheel, and the smoothpedalling qualities of the bicycle being preserved, a bicycle fittedwith such a driving wheel differing from a bicycle provided with anordinary wheel only by the additional weight of the driving unit.

A further object of the invention is to arrange the speed change gearcoaxially with the wheel and to provide a strong and compact structure.

A still further object of the invention is to provide an integraldriving wheel which can be easily and economically adapted on a bicycleand will be interchangeable with a conventional Wheel.

With these objects in view the propelling unit according to theinvention essentially comprises a fixed circular housing accommodating arotary hub structure which is in rigid relationship with the drivingwheel of the vehicle and wherein are housed most of the mechanical partsrequired for the operation, the speed-change gear comprising a set ofloose pinions coaxial with the hub and each of which may be selectivelyand directly caused to rotate with the hub by means of a slidable key.

The engine may be integral with or secured to the circular housing andthe hub may be rigidly connected to a flange carrying the rim of thewheel or with a drum connected to said rim by spokes, said drumpreferably surrounding the fixed housing with a small clearance.

Further features and advantages of the invention will made clear fromthe following description; with reference to the appending drawing,which shows, by way of example, an embodiment of the invention andwherein:

Fig. 1 is a side elevational view of the driving unit.

Fig. 2 is a corresponding plan view.

Fig. 3 is a section on line 3-3 of Fig. 1, showing the attachment of theanchoring link on the rear fork of the bicycle.

Fig. 4 diagrammatically shows the transmission between the engine on onehand and the driving wheel and the parts associated with the engine onthe other hand.

Figs. 5 to '7 are sections on lines 55, 6-6 and 11 of Fig. 1 or Fig. 4.

Fig. 8 is a section on line 88 of Fig. 5.

Figs. 9 to 11 are sections on lines 9-9, l0l0 or I0Ill and ll-ll of Fig.l or. Fig. 4.

Fig. 12 is a section through the braking members of the clutch.

Fig. 13 is a side elevation thereof.

Fig. 14 is a side-view of a part of the enginestarting lever.

Fig. 15 is a section through line l5-l5 of Fig. 1.

Fig 16 is a section through line l6-|6 of Fig. 4.

As shown in Figs. 1 and 2, reference numerals l and 2 denote the tubularbars forming one side of the rear fork of a bicycle and 3 the lowertubular bar at the opposite side. Numeral 4 denotes the axle of the rearwheel 5.

The usual hub of the wheel is replaced by a drum 6, of relatively largediameter, rotatably mounted on axle 4 and connected to the rim of thewheel 5 through spokes 1.

Drum 6 is formed at one side with a rotary flange 8 and i open at theopposite side, where it surrounds in close relationship a fixed disc 9,adapted to support the elements of the driving unit, said disc 9 beingheld stationary by means of an anchoring link secured at one end to aboss 12 of disc 9 by means of bolts I! and at the other end either tothe pedal supporting structure or to the rear fork, for instance bymeans of a collar l3 formed in two parts, one of which is welded to saidlink.

Disc 9 preferably consists of a casting, serving as a housing protectoror carrier for the engine and associated parts. The crankcase of theengine, shown at M, projects laterally from disc 9 and has securedthereto the engine cylinder I5; the exhaust pipe I6 of the engine isprovided with a sound damping exhaust device I1.

At the end of'the crankshaft 20 is mounted "a sprocket 2!, which througha chain 22, drives a sprocket 23 adapted to rotate the bicycle Wheelthrough a clutch, a speed-reducing gear and a speed-change gear, whichwill be hereinafter Pinion 64 meshes with a pinion 95 (Figs. 4 and 5)forming part of a set of stepped pinions 65', 66, B1, integral with ashaft 68, supported in bearings 69-10 respectively mounted in disc 90.and in a partition H secured thereto.

Pinions 65', 66, 61 are constantly in mesh with loose pinions 12, 13, 14arranged between partitions H and the cup 9a thrust ball bearings 15,16, TI, 18 being interposed there between and serving to center saidpinions with respect to the rear wheel axle 4.

Said axle carries a hub 19 supported in ball bearings 80,8I, and securedto the flange 8 of described. The clutch control lever isshown at 24 andthe speed-change lever at 2:5. The starting. device, described below, isactuated by a lever 26, provided with an operating handle 2'!- and anoscillating spring plate 28, the purpose of which is described below.

' Fig. 16 shows in detail the connecting rod mounting. The crankshaft 29supported in bearings 29, 30 of the crankcase i4, is built up of twoaligned trunnions, respectively integral with fianges 3|, 32 of suchmass as to constitute a fly wheel substantially filling the crankcasel4, so as to reduce the overall dimensions and the weight to a minimum,whereas the connecting rod 33 is held between said flanges and ispivoted at its end to a crankpin 34. At one end, shaft 29 carries theabove-mentioned sprocket 2| and at the opposite end, a pinion 35 (Figs.6 and 16) for controlling the ignition magneto I9. Magneto I9 is housedin a recess 36 of a cup 9a. bolted to the disc 9 (Fig. 9) and its shaftcarries a pinion 31 operatively connected with pinion 35 through twointermediate meshing pinions 38-39 (Fig. 4) Said intermediate pinions(Fig. are identically mounted (this is why Fig. 10 corresponds to bothsections Ill-I0 and l9-l9 of Fig. 4) in recesses,

48 of the cup 9a, on stub-shafts 4|.

Sprocket-wheel 23 (Figs. 1 and 11) which is driven by the engine asabove explained is keyed to a shaft 42, supported in bearing 43-44 ofthe disc 9 and cup 9a respectively. On said shaft is cut a pinion 45,constituting the inner sungear of an epicyclic gearing and meshing witha planetary pinion 46, keyed to a shaft 4?, connecting the side walls48, 49 of the planetary supporting structure 59, coaxial mounted onshaft 42 with the interpositionof an antifriction bushing 5|.

Planetary pinion 45 meshes with an annular sun-gear or annulus 52, inrigid relationship with a brake-drum 53,. mounted in a recess of disc 9by means of a ball-bearing 55. Said brake drum may be held stationary bymeans of brakemembers 56, 51, pivoted about an axis 58 and controlled bya cam 59 (Figs. 12, 13 and Cam 59 is formed at the end of a shaft 59, towhich is secured a clutch lever 24, the clutch spring consisting of ahelical spring 6!.

Normally, spring 6| urges the brake-members against drum 53 and keepsthe latter stationary, so that an epicyclic motion is imparted to theplanetary supporting structure.

When the brake-drum is released by the cyclist operating the clutchlever 24, annulus 52 is idle and the planetary supporting structure 59remains stationary.

Movement of the planetary supporting structure is transmitted through apinion 62, formed thereon to an intermediate pinion 53 (Figs. 4 and 7)rigidly connected with a pinion 64, both being mounted on a shaft 65 bymeans; Q ball.- bearings 66, 61.

drum '6.' Said hub is positively connected by means of a sliding key,splines or similar means,

" with a sliding sleeve 82, having projections or splines of starformation 83 (Figs. 4, 5 and 8), adapted to engage corresponding shapednotches provided in the center portion of pinions 12, 13,

14, so as to positively connect any one of said pinions with hub i9.Pinions i2, 13, moreover comprise in the middle portion thereof circularcupped portions 89, 85, adapted to accommodate the projections 83,whereby pinions l2, [3, l4 become idle upon the hub 19.

Sleeve 82 is provided with a groove 86, adapted to beengaged by a stud81 (Fig. 5), carried by a lever 88, secured to a shaft 89 to which iskeyed the speed lever 25, a spring loaded ball 90 (Fig. 8) maintainingthe lever 25 in its various operative positions.

It will be seen that, the clutch being engaged (Fig. 11) rotation of theengine is transmitted through parts 2|, 22, 23, 45, 53-54, 65 to shaft63 and, through pinions 55, 66-61 to pinions l2, I3, 19, which areconstantly rotated.

According to the position of the speed lever 25,,

one or the other of pinions l2, l3, H is positively. connected with hub19 and the vehicle wheel, through the projections 83 of sleeve 82, oralternatively all pinions 12-13-14 are idle (dead center). ,There aretwo dead centers, corresponding to both cupped portions 84, 85.

Hub [9 carries a free wheel pinion 9i, connected by the usual chaindrive to the pedal gear, for allowing the bicycle to be foot propelledif desired.

The engine is started by means of the hand. lever 26 secured to a hollowshaft 92 (Fig. 5). Extending through the latter is a shaft 93, the innerend of which carries clutch teeth 94, file ing cooperating teeth formedat the end of shaft 68 and the outer end of which projects outwardly toengage a spring blade 28. In the position shown in Fig. 5 and in dottedlines in Fig. 14, spring blade 29 is pivoted away from shaft 93, and theclutch teeth 94-95 are disengaged. To start the engine, the operatorturns the spring-blade 26 to the position shown in full lines in Fig.14, wherein said spring blade urges the projecting end of shaft 93inwardly, thereby causing teeth 94, 95 to engage, and then depressespedal 21 (Fig. 1) to rotate shaft 68 and consequently, the engine, saidmotion being amplified by the transmission connecting shaft 68 to theengine crankshaft.

It will be observed that, when the speed lever 25 is at its dead center,the vehicle wheel 5' rotates freely with drum 5 and hub 19, with-- outdriving any part of the speed change gear, transmission, clutch orengine, so that the inertia.

of the rotating vehicle wheel is hardly greater than that of aconventional bicycle wheel.

The use of an outer chain drive 22 between the engine and the clutchprQVides. for ready replacement of the pinions 2|, 23 and for thepossibility of obtaining different transmission ratios according to theconditions of use of the motor bicycle (town driving, flat land or hillycountry etc.).

The invention is of course in no way limited to the details ofconstruction described above, which have been given by way of exampleonly.

I claim:

In a cycle comprising a rear for}; the combination of a power drivenwheel, an axle rigidly secured. to said fork, a circular housing carriedby said axle, means connecting said housing to said fork for holdingsaid housing against rotation, an internal combustion engine laterallysecured to said housing, a hub rotatably mounted on said axle insidesaid housing, a wheel concentrically and rigidly secured to said hub, aspeed change sleeve slidably mounted on said hub. speed change pinionscoaxial to said axle and carried by said housing, projections carried bysaid sliding sleeve and adapted to successively d engage said pinions,said sleeve and said pinions being disposed in the gap of said fork of acon ventional bicycle and like vehicles.

MARCEL VIRA'IEILE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 400,150 Weston Mar. 26, 1889904,721 Perillard Nov. 24, 1908 1,247,752 Van Antwerp Nov. 27, 19171,284,970 Anderson Nov. 19, 1918 1,421,545 Osborn July 4, 1922 1,870,761Wiasemsky Aug. 9, 1932 2,253,408 Watkins et a1 Aug. 19, 1941 FOREIGNPATENTS Number Country Date France June 2, 1923

